This invention relates to a moldboard assembly having a flexible moldboard sheet that is adjustable to change the contour of the moldboard to control the flow of material through the moldboard and the direction of discharge.
Most conventional moldboards are formed from metal into a desired shape depending upon its intended use. In some cases the moldboard is involuted to provide a flared discharge at one end for casting snow to one side or the other of the propelling vehicle. When it is necessary to discharge to the opposite side of the vehicle, however, the contoured moldboard assembly must be replaced with one flared at the opposite end. Changing a moldboard assembly is a time consuming and often difficult task that is made even more difficult because of the accumulation of ice and snow within the component parts of the plow. Typically the truck is "deadheaded" or returned to the garage when a conversion is necessary so that the plow can be worked on indoors.
A roll-over snow plow has been developed by the present assignee that permitted a moldboard, contoured for a right hand discharge, to be converted to a left hand discharge in a matter of seconds. The moldboard assembly in this piece of equipment has cutting edges running along the opposed lateral edges of the moldboard. A lifting mechanism is attached to the moldboard that lifts the moldboard, rotates it 180 degrees, and lowers it back into a plowing position when a conversion is needed. The operator does not have to leave the cab to make the changeover and no further adjustment to equipment is necessary. The rollover design has been found to be most useful in clearing large open areas such as parking lots and airport runways where wind is a factor or where the snow must be discharged into prescribed disposal areas.
The rollover plow requires additional equipment to carry out the conversion maneuver and therefore is heavier and relatively more expensive when compared to a more conventional plow.
Metal (steel) moldboards are heavy pieces of equipment and require a good deal of horsepower to propel. This, of course, results in higher fuel consumption. Snow also sticks or packs upon the working surface of the metal moldboard therein lowering the plow efficiency and again increasing fuel consumption. A lightweight plastic moldboard has been developed by the present assignee which, unlike a steel moldboard, does not have to be laboriously bent to a desired curvature during manufacture. The plastic moldboard is simply molded or otherwise formed into a sheet of desired dimensions and the sheet is then bolted upon a support frame. The plastic moldboard is not only lighter than its metal counterpart, but it also has a low coefficient of friction which prevents snow from sticking to its surface. The plastic moldboard has been proven to save up to thirty percent in fuel costs. However, once it is bolted to the frame, its shape cannot be altered.